The Energy Blog has some more about cellulosic ethanol and how this alternative fuel is closer to being a sustainable fuel than gasoline. U.S. Department of Energy data indicates “that for every one unit of energy available at the fuel pump, 1.23 units of fossil energy are used to produce gasoline, 0.74 of fossil energy are used to produce corn-based ethanol, and only 0.2 units of fossil energy are used to produce cellulosic ethanol.”
I immediately began to wonder how advantageous cellulosic ethanol compares to “grass power“? Renewable Energy Access chastized Professor Pimentel and took issue with his claims that burning biomass in the production of fuel from hydrogen conversion is a better form of renewable energy than converting biomass to biofuel. They argued that Pimentel in the March 2005 paper published in Natural Resources Research based his analysis on only one conversion technology.
I remained unconvinced because their argument, actually spin to promote a product, used projections rathen than production data. In their article they admitted that ethanol production is yet to be cost-competitive while pointing to a targeted cost of $1.30 per gallon for cellulosic ethanol produced by enzymatic reduction hydrolosis. The authors asserted that in comparison to acid hydrolysis and thermal gasification this process is the most efficient means of ethanol production from cellulosic feedstocks.
People like Engineer-Poet recommend cogeneration as the best use of biomass. Burn the crop residues (leaves, stalks, and cobs) along with perennial feedstocks harvested from marginal use areas having been grown without the benefit of fertilizer, irrigation, or pesticides, e.g., fast-growing hays like switchgrass and short-rotation woody crops like poplar for combined heat and power. Then use the electricity to charge the batteries in your electric vehicles.